Dynamometer



June 18', 1929. L. G. NlLsoN 1,718,175

' DYNAMOMETER Filed sept". 1e, 1926 2 sheets-sheet 1 10G. l1 12 B 110.16 11a. 8 18 June 1s, 1929.`

' L. G. NlLscN V1,718,175

DYNAMMETER' Filed sepi. 1e, 192s 2 sheets-sheet 2 Patented June v18, .1929..

UNITED STATE s PATENT oFF-ICE.

LA RS G. NILSON', OFHOBOKEN, NEW JERSEY. i

DYNAoMmEn.

Application led September 16, 1926. Serial No. 135,85L`

I This invention relates to improvementsin rotary absorption dynamometers of the so -called Webb7 type, as described in United' States Patent No. 669,568, in which the fric# tion of revolving disks in a liquid is used as 4a medium for converting kinetic energy into heat. A numberof dynamometers operating on this general principle are in use.

In order to fully7 show 'the advantages and importance of my improvements, which con- 1 sist of certain novel parts and combinations of parts as will be pointed out with particuas water, is taken in at'one side of the revolving element close to its hub and has its outlet through selected openings located near the periphery7 of such element on the same side, the selection ofthe drainage-point being based upon the amount of power to be absorbed by the dynamometer as dependent upon the depth ofwater in the casing. l

Experience with dynamometers thus constructed shows that, as the result of centrifugalv action on the entering liquid, the depth of Water varies considerably from one side of the revolving element tothe other.

4 The lack of uniform circulation thus resulting cuts down very considerably the braking efficiency of the mechanism, by reason of the frictional effects on the different plates being Very non-uniform. Again, `the faulty circulation causes the formation of steam pockets which further .reduce the effective at all of proper rotor balancin friction surface and result in more or less violent fluctuations in the absorbed load.

The present mechanical construction of dynamometersof the type under consideration is not practical, since it does not admit and there lare no means of fastening toget er the various parts in groups for. rapid final assem bly. f The. stator plates must be assembled coincidentally with the rotor plates and inspection, repairs or replacement of either of .these elements demands the extensive dismantling of the dynamometer. The very important matter of having the proper provision for keeping water out of the bearings is not `adequately taken care of.

.. With'.'t`l1e foregoing operating disadvantages in View, .my invention provides for means to. supply. an abundance of water or other fluid to the axial region of the revolving element, in such manner 'that it is .i

evenly distributed to the friction surfaces and afterwards collected in a region posterior to the stator friction element for final.

proved construction for Y a self-contained rotor, a dlvided casing, means to permit of group assembly of theistator plates, means for anchoring such groups to the casing, and

liquid from entering ejection. There are also provided an imy V central shaft. This central shaft is intended for direct coupling to the prime mover under test and also to such other type of mechanism, such as an electric dynamometer, as

may bedesired for starting purposes or for the measurement of small loads, in which case it' can be run free of the tubular shaft. Means are provided for coupling the tubular and central shafts so as to engage the main dynamometer as desired.

The various features of, novelty which characterize my inventionv are pointed out With articularity in the claims annexed to and orming a part of this specification. For a better understanding of the invention however, and the advantages possessed by it, reference will be had to the accompanyirm; drawings and descriptive matter, in which I have illustrated and described some of the possible various embodiments of my ,inven' tion.'

In the drawings:

Fig. 1 is a vertical end View of the dynamometer.

Fig. 2 is a vertical side view of the dynamometer.

Fig. 3 is a vertical side view, in section,v

. lof the dynamometer.

rotor disk spacing nuts.

drum 6, annular disks 8, spacing nuts 7 Fig. 8 is an inside view of one of the annular nozzles, in which part of the first cover plate has been broken away.

Fig. 9 is an enlarged cross-)section of a water-seal device and adjoining parts.

Referring to Figs. 2 and 3, a central shaft 1 has an enlarged splined portion 2 near one end, and a collar 3 near the other end, the latter for taking care of end thrust in reference to a main tubular shaft 4. Two bearing shells 5 and 5 separate and retain `the two shafts concentric with each other.

described.` On the points of the spur teeth 6 a helicalscrew thread 6s is cut for the purpose of receiving spacing nuts or collars 7.

A number of disks 8, preferably annular 1n form and perforated as shown, which have inwardly projecting teeth at their centers to engage with the teeth 6c, are mounted uponthe drum 6 and spaced from each other by means of the spacing nuts 7, shown in detail in Fig. 7, which latter are centrally threaded to engage with the screw threads 6e and provided with radial openings 7a. At each end of the drum 6 and screwed upon the threads 6e is a clamping nut 9 which is provided with an inwardly projecting ange for the purpose of preventing escape of the supply liquid. Thel and clamping nuts 9 combine with shaft 4 to form a rigid self-contained rotor which may be readily assembled or dismantled, and adjusted for runnin balance. v

Castings 10 an 10, with end bells 17, the whole securely fastened together by means ofthe bolts 10b and 18, provides a water-tight casing. The end bells 17 act also as supports vfor the dynamometer structure as a whole and have extended hollow Journals which engage with the bearings 19, the latter being mounted, upon the pedestals 38 and secured thereto by means of the lock nuts 20. Attached to the interior of the casing portions 10 and 10aL and secured ject interiorly, as shown, into the spaces between the rotor disks. arranged circularl about each of the end bells 17 provide for water supply. These nozzles, designated as 21 and shown in vertical section in Fig. 3 and in inside view in Fig. 8, consist -of cored castings attached to the inner surfaces of the end bells 17 by means of the screws 22. Holes 21a which are tapped for standard pipe thread receive water supply pipes which pass through clearance holes 17a in .the end bells 17. The orifices of the nozzles 21 are each formed of .two curved annular plates 21" and 21c (see also Fig. 9) fastened respectively to the inside and to thebottom of the casting 21. A plurality of openings 16 are provided circularly about the castings 10 and 10a for water egress. 'As will be seen, the casing portions 10, 10a, end bells 17 supporting bars 12, lsemi-disks 11, 11a and nozzles 21 combine to form a rigid self-contained stator element which may be readily assembled.

Centrally about the assembled casing portions 10 and 10 and secured thereto by bolts are two blocks 35, as shown in Figs. 1 and 4. One of these blocks is intended to engage with ya scale or other connection for the purpose of measuring the torque acting upon the stator element and the other provides for lattaching weights for balance of the stator element, as in a manner well known to those versed in the use of dynamometers.

The ball-bearings 30, shown in Fig. 3 and in detail in Fig. 9, retain shaft 4 and end bells 17 in proper relation,v the inner ball races being clamped to the shaftY by lock nuts 31 and water seal ring 25 and the outer races being secured by thecombined medium of theend bells 17 and water seal ring 26. Two oil and water seals, shown in det-ail in Fig. 9, which are located one at each side of the rotor between the bearings430 and the spider 6, provide for preventing the escape of water and the damage to the bearings conseguent thereto, as also to prevent the harm ul splashing of oil. comprised of rings 23, 24 and 25 which are secured to the shaft 4, and rings 26 and 27 which are clam ed between and held by end bells 17 an nozzle castings 21. Soft rubber rings 28, also secured at their outer edges between rings 27 and nozzle castings 21, and which freely contact with rings 24 are provided for checking the flow of water toward the bearing 30 in the event that the housing is filled with water when the dynamometer is at rest. Felt ring 29 secured between rings 26 and 27 provide barriers against oil-splashing from the bearings 30 to the rubber rings 28. Not'shown on the drawings are provided means for, supplying lubrication to the bearings 5 and 30 and also means .for draining the annular spaces 32,-

33 and 34. i

While any type of clutch may be used for Annular nozzles,

These seals are n Having thus described the features of -the preferred form of my invention, its operation and method of use will be clear from the following:

The engine, motor or other device, the torque ofwhicli it is desired to measure, is coupled to oneend of shaft 1. The stator ofthe dynamometer is balanced and engaged with a weighing device through the .medium of the'blocks 35. Connections for the supply liquid. are made (preferably through the medium of flexible hose) to the annular nozzles 21 at each side of the rotor,

' and one or more of the exhaust 'openings 16 'are connected to a drainage system `preferably by hose). When the torque device un- .der test is s tartedjand shaft 1 is coupled to1 shaft 4, ther'otor element of the dynamometer revolves. ',The resultant turning movement onthe stator will be very slight, being due onlv to bearing friction andthe friction caused y the disturbed air between the rotor and stator plates. When water is introduced into the interior of the drum 6, through the nozzles 21, centrifugal action will ktend to uniformly diffuse it through the vents 6d of the drum and vents 7a of the rotor disk spacing nuts 7 to the spaces between the rotor disks 8 and the statorV plates 11 and 11,

, thence to be drained by the openings 16` The presence of the water in the interspacial regions of lthe dynamometer rotor and stator elements results in frict-ional resistance to the motion of the rotor element. The resulting turning moment acting on the stator, which is measured by a scale mechavnism linking one of the casing blocks 35, is

dependent upon the friction 4between the rotor disks and the water, the shearing action on the water acting at Athe edges 'of the rotor disk perforations, and also upon the momentum of portions of water caught in s uch perforated portions and thrown by centrifugal action ,against the stator plate elements.

The amount ofpower to be absorbed by the dynamometer may vbe controlled either by measuring Aor regulating the actual flow or quantity of water fed into the interior of .the casing through the -nozzles 21, in which case the exhaust openings 16 should be free" to let the water escape with .as little 4back pressure as possible. Or, the water exhaust V may be restricted until'a solidannulus of liq- .uid is built up in the casing'to'the desired depth, just sufficient entrance liquid being introduced 4to keep the temperature within reasonable limits- More s ecigfic meansand methods for contr'olling t e power absorption are not introduced into this specilica. tion, as I intend lto-make these the subject of an additional patent application.

`While, I have more or less specifically mentioned water inI speaking of the circulating medium introduced into my improved dynamometer for the purpose of converting kinetic'energy into heat, it will be understood that a wide-variety of liquids or fluids may be us'ed. For example, oils, or very heavyliquids such asmercury may be used with very high efficiency.

lVliile in accordance with the provisions of the statute I have disclosed and explained the best forms of my invention nou.r known to me, it will be apparent tot-hose skilled in the art that changes may be made in the modes of operation and forms of apparatus disclosed without departing from the spirit 4 of my invention, and thatccrtain features of the invention may sometimes be used withoutl a corresponding use of other features.

lI claim: 1. In a dynamometer, the combination with a plura ity of plates and a revolving shaft with attached disks having surfaces opposed to and spaced from the surfaces of .said plates, of a liquid interposed to resist the motion, vand means including a vented spider mounted on and surrounding said revolving shaft for uniformly distributing said. liquid.

2. In a dynainometer, the combination with a plurality of plates andv a hollow revolving shaft with attached disks having surfaces opposed to and spaced from the surfaces of said plates, of a liquid interposed to resist the motion, and means including a vented spider on the said hollow revolving .shaft for uniformly distributing said liquid.

3. In a dynamometer, the combination with a rotatable shaft of a casing sleeved thereon, plates keyed to said casing, a drum splined on said shaft, disks mounted on said drum and alternating with said plates, an'd means including vented spacing nuts for conducting a fluid from the interior of said i drum to the surfaces of said disks and'plates. 4. In a dynamoineter, the combination with a rotatableshaft of a casing sleeved thereon, plates keyed to said casing, a drum splined on said shaft carrying disks, each of which has inwardly projecting teeth at lts center, -and lmeans for conducting liquid tol and from the surfaces of said disks and plates. 1 x 5. Ina dynamometer, the combination with a rotatable shaft of, a casing sleeved thereogv plates keyed to 'said casing, ,aQd'rum lp to said shaft and havin ports therethrough,

disks mounted on said rum andalternating lwith said plates, and meansincluding vented A spacing nuts for conducting a liquid through said drum to the surfaces o f sald disks land plates.

, v 6. In a dynamometer, the combination with a rotor element comprising a plurality of'A spaced disks, of a stator element comprising a pluralit of divided plate members, said ,divided p ate members being preassembled in rigid groupsand-mounted in alternat ing space relation with the said disks.

7. In a dynamo'meter, the combination with a `rotor element comprisinga plurality of spaced disks, of a stator element comprising a vplurality of spaced plate members, said plate' members being divided, and. means for` rigidly sub-assembling said plate members to facilitate their mounting in alternatv ing space relation with said disks.

8. In a dynamometer, the combination with a rotor element comprising `a plurality of spaced. disks, of a stator element comprising Aa plurality of divided plates, and means for rigidly supporting said divided plates in groups in definite space `relation with the said disks.

9. In va dynamometer, the combination with a plurality of plates and a revolving shaft with attached disks having surfaces opposed lto and spaced from the surfaces of said plates, of means for supplying a liquid to the spaces between said plates and said disks includin a-nozzle having angannular orifice surroun ing said shaft, and means including a vented spider mounted on said revolving shaft for uniformly distributing said liquid;

l0. In a dynamometer', .the combination 'l yannular discharge orifice surrounding said shaft for directing theV fiowofY said liquid in an axial direction to the interior of said spider. i -V 11. In a dynamom'eter,.uthe combination with a stator element comprising a casingmember provided with a lurality of plates and a revolving` shaft, with 'attached disksy osed to and'lspaced fromhaving surfaces op the surfaces 'of sai plates, of a plurality of nozzles4 .at least one at each end vof said stator member, each of' said lnozzles being provided with an annularorifice surrounding said shaft for supplying a liquid-in anaxial direction, anda ventedspider mounted on and surrounding said shaft communi" eating with said nozzles to receive the liquid from said orifices and to dis'tributesaid liquid uniformly `between said plates and 'said disks. y Y

Signed at New York in the county of New York Iand 4'State of New York this 11th day of September A. D. 1926.

LARS'G. NYILsoN. 

